Steve Davis could tinker with Crewe Alex’s formation in their final pre-season friendly at Chester tomorrow (Saturday, 3pm) – as he makes final preparations for the 2015-16 opener against Port Vale.

The manager has sent his side out with a back four in all of the warm-up games so far – and the Railwaymen have been undefeated throughout.

But Davis said on Tuesday he could yet start with three centre-halves against the Valiants at Gresty Road, and may try it out at some stage during the game at the Lookers Vauxhall Stadium.

He said: “We are looking at one or two different ways of setting up, we haven’t gone with a three yet but that’s something we are working on in training because that’s something we might revert to come the start of the season.

We are looking at different systems to catch people out, we did that last season and it worked.

“We will look before the Vale game to see what the best system is for us to start with. They will be raring to go on that first day.

“The players who are going to start the season need to get as much game time as possible. The weekend will provide them with another 90 minutes.”

Crewe got their best results while playing with three central defenders and wing-backs last season. When they switched to that system, their goals-against record improved dramatically and results improved despite them being short on firepower at the other end.

But then they were flush with centre-halves, with loan man Alan Tate supplementing Harry Davis, George Ray, Jon Guthrie, Anthony Stewart and, for some of the time, Adam Dugdale.

Now with Tate, Stewart and Dugdale departed – and Davis in a race against time to recover from a knee injury – Crewe have fewer options, although youngster Toby Mullarkey has impressed at times during the summer.

Manager Davis still wants to strengthen his rearguard, and is expected to take the strongest squad at his disposal to face Conference side Chester.